Presently various types of structured documents are widely used in different engineering fields, which creates a commercial demand for automatic knowledge extraction or for interpretation systems to reuse previous drawing contents. Engineering table drawings are one such type of structured documents which represent structured knowledge in a compact and efficient way. As a result, automatic knowledge extraction or interpretation of engineering table drawings has been an important topic in document analysis today.
Currently, most available text detection methods cannot be used reliably for engineering drawings. One common approach for text detection in image is a stroke width transform. The stroke width transform works on a principle that text in images have constant stroke and non-text regions have non-uniform stroke width. However, in case of digital engineering drawing, both text and non-text regions have constant stroke. Therefore, the stroke width transform is unable to differentiate between text and non-text components.
The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.